The role of carbon nanotubes in enhanced charge storage performance of VSe: experimental and theoretical insight from DFT simulations.

Herein, we report the hybrid structure of metallic VSe and multi-walled carbon nanotube (MWCNT) based hybrid materials for high performance energy storage and high power operation applications. The dominance of capacitive energy storage performance behaviour of VSe/MWCNT hybrids is observed. A symmetric supercapacitor cell device fabricated using VSe/80 mg MWCNT delivered a high energy density of 46.66 W h kg and a maximum power density of 14.4 kW kg with a stable cyclic operation of 87% after 5000 cycles in an aqueous electrolyte. Using density functional theory calculations we have presented structural and electronic properties of the hybrid VSe/MWCNT structure. Enhanced states near the Fermi level and higher quantum capacitance for the hybrid structure contribute towards higher energy and power density for the nanotube/VSe.